1. Field of the Invention
The present invention relates to lead salt photodetectors and more particularly to midwave infrared lead salt photodetectors.
2. Brief Description of Prior Developments
The achievement of near-background limited (for 180 degree field of view) midwave infrared detector performance at room temperature mandates simultaneous responsivity (signal) and high impedance (for low-noise). Generally good responsivity is not compatible with high resistance and currently available room temperture photoconductive detectors often sacrifice response for high impedance due to the low mobility and lifetimes found in midwave semiconductors at these operating temperatures.
In the photodetector prior art air annealing of thin lead salt films and material compensation for impedance. The disadvantage of this procedure is that it may lead to surface damage and poor photoconductive gain.
There is, therefore, a need for improved photoconductors and methods of their manufacture that overcome the disadvantages of the prior art.